How to Protect Your Polished Plaster Finish

A Professional Guide for Long-Lasting, Luxury Interiors using Venetian polished plaster

Polished plaster is a premium wall finish chosen for its depth, elegance, and timeless appeal. From contemporary London apartments to high-end Surrey homes, it delivers a tactile, architectural quality that paint simply cannot match and is super customisable.

However, polished plaster is not a “fit and forget” finish.

To preserve its beauty, sheen, and performance over time, the correct protection, sealing, and care strategy is essential. This guide explains where to use Venetian plaster, and exactly how to protect polished plaster properly, based on real-world experience installing and maintaining decorative plaster finishes in residential and commercial interiors.

What Is Polished Plaster?

Polished plaster (often referred to as Venetian polished plaster) is a lime-based decorative finish made with fine marble dust. Applied in thin layers and compressed during application, it creates a smooth, stone-like surface with natural movement and depth.

Unlike regular paint, polished plaster:

• Is breathable

• Develops character over time

• Reacts to light, touch, and environment

Because it is a natural mineral finish, correct protection is part of the specification, not an optional extra.

Why Polished Plaster Needs Protection

While durable, polished plaster is not inherently waterproof or stain-proof. Without appropriate protection, it can be vulnerable to:

• Moisture ingress in kitchens and bathrooms

• Staining from oils, soaps, or splashes

• Loss of sheen in high-touch areas

• Surface marking from abrasion or impact

Professional sealing and ongoing care dramatically extend the lifespan of the finish and keep it performing as intended.

Sealing Polished Plaster: The Most Important Step

Sealing is the single most critical factor in protecting polished plaster; it needs to be cared for as the premium, luxurious finish that it is.

A professional-grade sealer or wax system:

• Creates a protective barrier against moisture and stains

• Improves cleanability without blocking breathability

• Enhances depth and sheen

• Tailors performance to the room’s use

Wax vs Sealer. What’s the Difference?

Wax finishes

• Enhance sheen and softness

• Suitable for feature walls and low-contact areas

• Protects against hand marks and daily usage

Technical sealers

• Offer higher resistance to moisture and staining

• Essential for bathrooms, kitchens, stairwells, and commercial spaces

At Signature Walls, the sealing system is specified per room, not as a one-size-fits-all approach.

How to Clean Polished Plaster Safely

Incorrect cleaning is one of the most common causes of damage, which can deteriorate the surface, leave scratches or remove the lustre.

Recommended cleaning method:

• Dust regularly with a soft microfiber cloth

• Use a slightly damp cloth with pH-neutral soap only

• Dry the surface immediately using a clean, lint-free or microfibre cloth

Avoid:

• Abrasive sponges

• Bleach or acidic cleaners

• Alcohol-based sprays

Harsh chemicals can dull the surface, strip wax layers, and permanently alter the finish.

Protecting Polished Plaster from Physical Damage

Although this material is natural in makeup, it is still a decorative finish, not structural concrete.

To reduce wear:

• Use furniture buffers near plastered walls

• Avoid repeated contact in narrow circulation zones

• Use proper fixings when mounting items

• Protect finished walls during later trades or furniture installation from knocks and scratches

In high-traffic areas, specifying the correct finish and seal from the outset is key. In some cases, an alternative material from our range may be more suited, such as Microcement; we can advise on the best outcome.

Environmental Factors: Moisture, Heat & Ventilation

Polished plaster performs best in stable internal environments.

Best practice includes:

• Adequate ventilation in bathrooms and kitchens

• Avoiding prolonged condensation on the surface

• Maintaining consistent indoor temperatures

Poor ventilation is one of the leading causes of long-term finish degradation, especially in wet zones.

Long-Term Maintenance & Resealing of Polished Plaster

Depending on location and usage, polished plaster may benefit from professional maintenance every few years.

This can include:

• Resealing to refresh protection

• Re-burnishing to restore sheen levels

• Localised repairs instead of full replacement

When installed and maintained correctly, polished plaster can last decades, ageing gracefully rather than deteriorating.

Frequently Asked Questions About Polished Plaster

Can polished plaster be used in bathrooms?

Yes, polished plaster can be used in bathrooms, but only when the correct plaster system and sealing specification are used. Wet areas demand enhanced protection, or to choose another material which is better suited to wet environments, such as Microcement.

Is polished plaster waterproof?

No. Polished plaster is breathable by nature. Water resistance comes from the sealer, not the plaster itself. We do not recommend installing this product in shower enclosures or other direct wet areas.

How long does polished plaster last?

With correct installation, sealing, and care, polished plaster can last for many years with minimal intervention.

Why Specification Matters More Than the Product

Many problems attributed to “polished plaster” are actually caused by:

• Incorrect substrate preparation

• Inappropriate sealers

• Poor detailing in wet areas

• Inadequate client guidance and aftercare

This is why professional specification and aftercare advice are just as important as the finish itself, care for the installation, and it will remain in good condition for many years to come.

Expert Polished Plaster Installation & Aftercare

Signature Walls

At Signature Walls, we design, install, and protect polished plaster finishes for high-end residential and commercial projects across London, Surrey, and the Home Counties.

We don’t just apply finishes, we engineer them to last.

👉 Speak to our team for tailored advice on polished plaster protection, maintenance, or specification.